Typically, an electronic device has redundant power supply modules. When the load power consumption of the electronic device is very high, it is shared among the individual power supply modules. However, due to the effect of power saving techniques applied in the electronic device, when the load consumes less power, it is necessary to consider how to reduce the power consumption of the redundant power supply modules themselves.
From the perspective of electrical characteristics of a power supply itself, a power supply can reach its nominal efficiency only when its load consumes over 20% of its nominal power. When the load consumes less than 20% of its nominal power, the efficiency of the power supply itself drops rapidly and will be typically maintained at around 50%. When an electronic device has a number of power supply modules and its load consumes little power, each power supply module is assigned with little output power, resulting in low efficiency. In this case, the overall efficiency of the power supply will be very low.
Conventionally, all redundant power supply modules are connected in parallel and are current equalized and connected for output via a substrate. Only one system activation signal is input to a distribution board and all of the redundant power supply modules are turned on/off concurrently.
The inventors recognized at least the following problems in the prior art. During a process in which the redundant power supply modules supply power, all of the redundant power supply modules have to be turned on or off at the same time. In other words, it is impossible to turn on some modules while turning off the others. However, since the load power consumption of the electronic device is relatively low, each of the redundant power supply modules may be assigned with low power consumption, resulting in low power efficiency. Human intervention can be introduced. However, it requires operators to have full knowledge of the load power consumption requirements of the entire electronic device as well as the output power of each redundant power supply module, which is very difficult for the operators.